Transformer for electric metal-working apparatus.



UNITED STATES PATENT OFFICE.

ADOLPE F. RrEfrznL, or oHanLEssoWN, Britons xaLaND, AssreNon To 17m-veneer. ELECTRIC WELDINGl oom'amr, oF New YORK. N. Y., A conroxmgou or NEW Speciction o! Letters Patent.

TRANSFORMEB. Fon nI-.Eczria'lc Meran-waarna ArrABazrUs.

Patented Feb. v1;.,191-a.

application. 111e@ Ienvary 12, ,19.10- Serial NO- 537,653-

To qll whom t may concern:

Be it known that I, Ammin RIM/inn, a citizen of the United States, and aresident of Charlestown, in the Acounty of Washington and State of Rhode Island, have invented certain new and useful Improvementslin Transformers for Electric Metal- VVorking Apparatus, of which the following is a specification. y

My present invention relates to improvements in static transformers and more particularly to transformers ofthe class used in electric metal working apparatus.

One of the ob]ects of my invention is to provide a single ltransformer in which more than one weld may b e made .0r more than one section of metal heated, simultaneously, if desired, and in which there will be an even distribution of current to each weld or section of metal to be heated.'

Another object of my invention is to provide a transformer in which-two different voltages can be obtained from the secondary without! in any Way varying the primary winding or altering the magnetic field.

Other objects'of my invention will be evident from the following detailed description of some of the applications to whichA the same may be put.

In carrying out my invention I employ a transformer all the parts of whose secondary are subject. to the same magnetic influe-nce and the secondary is provided with preferably three terminals7 one common to the other two and disposed preferably equidistant between them so that there will be at all times an equal distribution of the current from the common terminal to each of the other` two terminals.

The transformer secondary comprises at least two turns connected in series and provided with terminals at the ends of t-he turns and a common terminal secured to the connection between the turns, so that a certain voltage is Vobtained between the common terminal and each vof the end terminals and a current of greater voltage is obtained between the two end terminals. For instance. if the 'line voltage is 300 and there are 150 turns in the primary winding, the voltage seioss the terminals ot a secondary having i 1 one turn would be two volts and in a rSieefmdary having two turns connected in r there would be four volts across the (er....als. ln other wor-s, two volts would he .chained fa ach tum in ne sesam,

so that if the seccudary consists. of two turns cgirineetcd in series', .four volts would he Obtained aeress the terminals. Ori the-ends of the turns- A third .terminal may be @Oil- Anested t0 the turns at the, .enuectioii lietween them, s o that there would be one turn between t-he terminals at either end of the secondary and the third terminal, iii which case two volts would be obtained he- 'tween the third terminal and either or both 0f the Others- As all the parts of the secondary are subject to the influence of vbut one prlmary and core, the voltage between the common terminal and each of the end terminals is always the same as it would b impossible to vary one without the other.

Each of the terminals is provided with work-contacting or engaging devices Vwhereby 'a weld or similar electric metal working operation may be effected b etween the common terminal and each end terminal and it will be assured that eaoh weld will be perfectly made and of the same strength. A secondary having two or more turns is used, andthe end terminals may be used to give a preliminary heating to the work after-.which the third terminal may be brought into action to complete the welding.

My invention permits welds to be effected by making Contact with but one side of the work and thereby a machine may be suspended entirely above the Work and an unlimited and unrestricted area below be obtained, whereby work of large surface area can be handled.

My invention consists in the novel construction an'd formation of parts hereinafter more particularly described and then specified in the claims.

In the accompanying drawings-Figure l illustrates a side elevation of an electric metal working apparatus having my invention embodied therein. F ig. 2 is a transverse vertical section taken on the line A A Fig. l. Fig. 8 is a front elevation of another form of apparatus embodying my invention. Fig. 4 is a plan view of the same. Fig. 5 is a side elevation.

Referring more particularly to Figs. l `and 2, the secondary proper preferably consists of two turns lying in parallel planes and Connected in series by a transverse cross-over or bridging piece along the lines of the secondary structure shown and described in my prior Patent No. 649,179, dated May 8, 1900. While I prefer to use a combination of solid and flexible secondary as described in the said patent, it will be understood that I do not limit myself to such a structure, but owing to the readiness with which it adapts itself to use with my present invention I herein show my invention in one of its forms as applied to a secondary so constructed. The secondary pref erably consists of two turns or partial turns of cast metal 1, 2 spacedl apart to allow a depository for the primary coil 3, the usual laminated core being indicated at 4. The said turns are connected in series by a transverse connecting strip or bridging piece 5, the last side of each turn being preferably completed by a flexible bar or strip secured to the end of each turn whereby flexible terminals 6, 7 are secured. To the end of the flexible bars formingv lthe terminals, work engaging devices here shown for the sake of illustration cont-acts 8, 9 respectively are secured. Either oneor both of these contacts may be. movable to and awayfrom each other by any suitable mechanism. 10 indicates a third terminal connected to the bridging piece'5 in any suitable manner, said terminal being provided with a coperating work engaging contact 11 preferably slidably mounted lon said' terminal whereby it canl be brought into and out of engagement with Athe work. lWhen the apparatus is constructed with work-engaging cont-acts as shown the workindicated at 12 is suitably supported between the coiitacts 8 and 9 so that when the contacts are brought together they will grip the work in line with the point or points of intended wel-d. In the. case illustrated, the work consists of a metal she-ave or pulley which it isv desired to weld together at the points 13, 14. The third or common contact 11 is brought up into engagement `with the work between thecontacts and at the other side of the point or points of desired weld from the contacts 8, 9. Upon the circuit being completed, by the engagement of the contacts 8, 9 with the work or otherwise, the current will flow in equal amounts from the common contact 11 to each of the contacts 8 and 9, which supply t-he necessary pressure and the parts are welded at the points 13 and 14. The voltage between the contact 11 and each of the contacts 8 and 9 will be equal and therefore the amount of current flowing in both directions will be the same, as around each gap there is one complete turn of secondary. Obviously, the welds might be made successively instead of simultaneously, if desired, by bringing but one contact 8 or 9 int-o engagement with the work at one time.

In the form of my invention shown in.

again preferably employed, the turns beingY connected in series by a bridging piece as before, but in this case the complete lturns are preferably solid and provided with solid terminals 15, 16 secured to the ends of the turns. Also the primary coil 3 is preferably divided into three parts connected in series and located against each face of the turns 1, 2 although the primary might be otherwise located if desired withoutdeparting fro-m the invention. 17 indicates the common terminal connected to the bridging piece 5 and each of the terminals are provided with guide plates 18, 19 and 20 in which platens or blocks 21, 22 and 23 respectively slide. The sliding platens or blocks are caused to slide up and down in their guides by any suitable mechanism, (no-t shown) and, as will be observed, are in electrical connection with the secondary, there being one turn of secondary between the common platen 17 and each of the end platens 15, 16 and two turns of secondary between the platens 15 and 16.

The pla-tens 21, 22 and. 23 are each provided at their lower ends with work engaging contacts 24, 25 and 26 respectively, the contact 25 being connected to the bridging piece 5 and common to the other two contacts. The work indicated at 27 is suitably supported below the contacts, it being noted that the entire apparatus is above the Work and when the contacts are brought into engagement therewith, the current enters the work at one face only. By these means large areas of work, such as sheet metal doors, and the like, can be welded or otherwise worked, there being an unrestricted area below the contacts. In such work where it is practically irnpossible to effect the necessary end pressure usual to complete the weld in buttvwelding, the edges of the two pieces of metal are first butted together and the contacts 24 and 26 brought down upon the work, the current flowing from one to the other and the work preliminarily heated after which the common contact25 is brought down, a piece of wire being inserted between it and the work and over the meeting edges thereof, the current then distributing from the contact 25 to each of the contacts 24 and 26 in equal amounts and the wire welded to the both pieces of work, thecontact 25 supplying the necessary welding pressure.

Owing to the large area of metal in contact along the edges of the work more pressure or voltage is necessary to overcome the resistance between the contacts 24 and 26 than is necessary to effect the welding in ot the wire, by which limited area of contact with the edges is formed. This increased pressure is obtained by the contacts 24 and 26 being supplied from two turns of sec- Ondary as previously described, Whereas rosanna there is but one turn between the contact 25 It will be understood that the embodimentv of my invention as shown and described is for the purposes of illustration only and is not limited to the details of construction, but various other ways of carrying the invention into effect may be employed without departing from the spirit thereof, as set forth in the appended claims.

What I claim as my invention is:

1. A metal working transformer'secondary all the parts of which are influenced by a common primary and having three coperating terminalsA whereby the work heating current may be .caused to flow from one terminal simultaneously to both the other terminals.

2. A metal working transformer secondary all the parts of which are influenced by a common primary and a single core and having three coperating terminals whereby the Work heating current will normally .be evenly distributed between one of said terminalsv and each of the others.

3. A metal working transformer secondary comprising two or more/turns connected 1n series, termlnal blocks secured to the ends of said turns and av cooperating terminal block secured to the connection between the turns.

4. `A metal working'transformer secondary comprising two turns connected in series and three terminals provided withcooperating work-engaging devices, one of said terminals being common to the other two and secured to the connection between the turns whereby current may flow in equal amounts from said common terminal to each of theother terminals.'

5. A metal working transformer secondary comprising two or more turns, bridging pieces connecting the turns and an intermediate terminal common to the end terminals and connected to said bridging piece, said terminals supplying heating current to the work whereby current of one voltage will be obtained acrossethe gap between the common terminal and each of the end terminals and current of a different voltage will be obtained across the gap between the end terminals.

6. A metal working transformer secondary comprising two turns lying in parallel planes connected by a bridging piece and a terminal common to both turns secured to said bridging piece whereby current of one voltage will be obtained between the common terminal and the end terminals and current of a different voltage between the end terminals and coperating work-engaging devices connected respectively tto the extremes of the secondaryand to the terminal secured to the bridging piece.

7. A metal working transformer secondary comprising two or more turns lying in parallel planes, a bridging piece connecting said turns in series and cooperating workengaging contacts connected to the ends of said turns and to-said bridging piece whereby heating current of two different voltages will be obtained.

8. A metal heating transformer secondary comprising two or more turns lying in parallel planes, a bridging piece connecting the turns in series, a single core for said turns and work-engaging contacts connected to the ends of said turns and to said bridging piece whereby current of two different voltages will be obtained, one of said voltages being approximately a multiple of the other.

9. A metal working transformer secondary comprising two or more turns and a transverse connection uniting the turns in series and three cooperating work-engaging contacts connected respectively to the ends of said turns and to said transverse connection.v

10. A transformer for electric'metal working apparatus comprising a secondary having two or more turns lying in lparallel planes, means connecting the turns in series and three coperating work-contacts connected respectively to the ends of said turns l and to said connecting means as and for the purpose described.

11. A metal working transformer secondary all the parts of which are influenced by a common primary and provided with three terminals, through which heating current is supplied to the work, two of said terminals having maximum difference-of potential and I the third being common to the other two but of an intermediate voltage. Y Signed at New York in the county of New York and State of New York this 8th day of January A. D. 1910.

ADOLPH F. RIETZEL.

C. F. TIscHNnn, Jr. 

